Upload
kaio-lukas-freitas
View
219
Download
0
Embed Size (px)
Citation preview
7/29/2019 13 Egg White
1/22
13. Egg WhiteRenate Landig
German Team
7/29/2019 13 Egg White
2/22
2
Task
White light appears red when it is
transmitted through a slice of boiled egg
white. Investigate and explain this
phenomenon. Find other similar examples.
7/29/2019 13 Egg White
3/22
3
Overview
Experiments
Structure of Egg White
Theory
Rayleigh Scattering
Similar Examples
Modified Rayleigh Scattering
7/29/2019 13 Egg White
4/22
4
Experimental Setup
7/29/2019 13 Egg White
5/22
5
Basic Experiment
Unpolarized white light
0.15 mm solid egg white
the screen behind the slice:
spectrum with sample
without
prism
7/29/2019 13 Egg White
6/22
6
Spectrometer
280nm: absorption maximum
Boiled egg (d=0.1mm)
7/29/2019 13 Egg White
7/22
7
Structure of Egg White
mixture of proteins in water
protein: 20 different amino acids
unfolding through heat input
reactions between proteins
unstructured network (random coil) density fluctuations scattering
Denaturated egg white:
Liquid egg white:
7/29/2019 13 Egg White
8/22
8
Scattering
Wave excites particles oscillation
Hertzs dipole
Scattering fields
7/29/2019 13 Egg White
9/22
9
Derivation of E-field
P
Er
_O
2
2
dt pdtdIdtdBE 0
2EE
rE
1
ckc ==
2
(1) tiepp
0=
(2)
sinE
(3)
(4)
sin
40
2
0
r
kEE=
7/29/2019 13 Egg White
10/22
10
Unpolarized Light
||
E
||E
||,0E
,0E
.
cos
4 0
2
||,0||r
kEE = 2
0
2
,0 sin4
r
kEE =
7/29/2019 13 Egg White
11/22
11
Rayleigh Scattering
2
||
22EEE +=
0
22
0
2
4
2
)cos1(
4 Ir
k
I
+
=
4
42 1d
= krIP
2
EI
The radiant power of one particle:
7/29/2019 13 Egg White
12/22
12
Extinction
xII
= e0
4
1ln
0 == x
I
I
Lambert-Beers Law:
Extinction:
nPn
I I
dI, dx
7/29/2019 13 Egg White
13/22
13
Comparison with Experiment
800nm 350nm
expected
measured
1
1.2
0.8
1.8
1.6
2
1.4
extinc
tion
[1]
-4254m10
2 5431
7/29/2019 13 Egg White
14/22
14
With Interference
2scatincsin2
cos
bkkrkr
rb
==
=
r
r
r
r
r
P
O
7/29/2019 13 Egg White
15/22
15
Modified Rayleigh-Scattering
2
2i
sin
)sinsin(1de
1)(
2
2
a
ka
kbA
AaR
a
a-
==
2
Rlgh )(RII
=
( )=
cos1
4 0
2
0
||
Rr
VkEEE
7/29/2019 13 Egg White
16/22
16
Dependence on
( )
+
=
ka
P
rIP
dsin
sinsin
2
cos11
d
2
2
2
2
2
2
(k) is only slightly dependant onk
2
1
P
)(k
7/29/2019 13 Egg White
17/22
17
Extinction- -plot2
1.8
extinctio
n
[1]
1.4
1.6
1
1.2
0.8
-2122m10
2.5 43 54.53.5
1.8
7/29/2019 13 Egg White
18/22
18
Similar Examples (1)
Sunset / Lunar eclipse
7/29/2019 13 Egg White
19/22
19
Similar Examples (2)
Milk in water
7/29/2019 13 Egg White
20/22
20
Similar Examples (3)
Polyethylene: e. g. white plastic bag
7/29/2019 13 Egg White
21/22
21
Similar Examples (4)
Ouzo in water
without
liquid
7/29/2019 13 Egg White
22/22
13. Egg WhiteRenate Landig
German Team